Slider for slide fasteners

ABSTRACT

A slide fastener has an improved slider in which elbow members of each of the angulated flanges defining the slider channel have a chamfered inner edge whereby the slider exhibits improved operational smoothness, increased conformity to the configuration of the fastener under lateral loads and reduced fastener binding, cutting and wear.

O United States Patent 1191 1111 3,872,553 Moertel Mar. 25, 1975 SLIDERFOR SLIDE FASTENERS 3,111,732 11/1963 Buir 24/20515 R 3,l70,207 2/1965Morin 24/2()5.l5 R [75] Inventor: gwrge Meml1 Conneautvllle! 3.6639965/1972 Heimberger et ul. 24/211515 R [73] Assignee: Textron Inc.,Providence, RI. Primary Examiner-Roy D. Frazier [22] Filed: Sept 18,1972Assistant Eraminer-Darrell Marquette [21] Appl. No.: 289,854 [57]ABSTRACT A slide fastener has an improved slider in which elbow [g2]members of each of the angulmed flanges defining the Slider Channel havea Chamfered inner edge whereby [58] Field of Search 24/205 15 R 205 11 R1 the shder exhlblts 1mpr0ved operational smoothness, 56 R f d increasedconformity to the configuration of the fas- 1 e erences tener underlateral loads and reduced fastener bind- UNITED STATES PATENTS ing,Cutting and wear 2362.274 l2/l958 Morin 24/205.l5 R 2 901.1105 9/1959Porepp 24/20515 R 2 Clamm 7 Drawmg Flgures 1 SLIDER FOR SLIDE FASTENERSBACKGROUND OF THE INVENTION 1. Field of the Invention The presentinvention relates to slide fasteners and, more particularly, to animproved slider for a filamentary fastener.

2. Description of the Prior Art The acceptance of slide fasteners for avariety of diverse applications has been substantial and wellrecognized, and efforts to improve their appearance, ease of operation,resistance to binding, locking ability and overall quality continue tobe made as new materials and manufacturing techniques are discovered.

By way of background, conventional slide fasteners typically include apair of elongated carrier tapes upon which are attached a series ofindividual coupling elements along one of the longitudinal edges of eachtape. Such elements have long been made of metal and are crimped orotherwise secured along a woven bead on the edge of each tape to formthe fastener chain. A slider defining a V-shaped channel is slidablydisposed on the chain and has a pull tab enabling one to selectivelyinterengage or disengage the chain halves by upward or downwardmovement, respectively, of the slider. 7

With the advent of synthetic materials, such as nylon, considerableattention has been directedtoward improving the construction of thecarrier tapes per se as well as the interengageable coupling elements.As a result, slide fasteners employing continuous coiled or serpentinecoupling elements formed from thin filaments of synthetic materials arenow inwidespread use and in a sense have .revolutionized the fastenerart. Such filamentary fasteners provide numerous advantages in manyapplications and are extremely economical to manufacture by reason ofthe simplicity with which the continuous formed filaments areconstructed and sewn. to the carrier tapes.

While many advances in the constrution of the coupling elements and thecarrier tapes have been made in the past, the overall sliderconfiguration-has remained relatively unchanged from its initial design,with the exception of various lock modifications made specifically forsynthetic fasteners. As-a, result of the unchanged slider constructionmodern filamentary fasteners often exhibit poor slider actioncharacterized by binding, stiffness and excessive wear. Particularlysusceptible to slider wear have been the exposed stitching threads usedto attach the filamentary coupling elements to the carrier tapes sincesuch threads were not present in the metalcoupling link fasteners forwhich conventional sliders were designed and, thus, were not consideredin the original design parameters. These threads are subject toexcessive wear and fraying by the slider since the threads are forcedagainst relatively sharp edges of the moving slider when the fastener isunder lateral tension as when the fastener is beingclosed.

SUMMARY OF THE INVENTION The present invention is summarized in that aslider for a slide fastener includes a main body member having a. pairof spaced, parallel wing members, a pair of flanges extendingrespectively from opposite lateral edges of each wingmember toward eachother to define a Y-shaped channel for slidably receiving the slidefastener, and each of the. flanges being chamfered along at least aportion of a longitudinal inner edge thereof whereby the channelconforms to the configuration of a laterally loaded fastener.

It is an object of the present invention to reduce operational effort ofa fastener slider while improving overall fastener performance.

This invention has a further object in the construction of a fastenerslider having fewer sharp edges and conforming to the configuration of alaterally loaded fastener chain. I

Another object of the present invention is to reduce slider binding andexcessive stitching thread wear while enhancing the smoothness ofoperation of a completed fastener.

Some of the advantages of the present invention reside in its freedomfrom binding, its smoothness in operation and its ability to provideimproved operation without cutting, fraying or otherwise damaging ordisrupting the fastener stitching threads.

Other objects and advantages of the present invention will becomeapparent from the following description ofa preferred embodiment whentaken in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a fragmentary plan view of afilamentary slide fastener having an improved slider according to thepresent invention;

FIG. 2 is an enlarged sectional view of the slider of FIG. 1;

FIG. 3 is a sectional view of a complete slider taken along line 3-3 ofFIG. 2;

FIG. 4 is a-sectional view similar to FIG. 3 taken along line 4--4 ofFIG, 2;

FIG. 5 is a sectional view similar to FIG. 3 taken along line 55 of FIG.2;

FIG. 6 isa sectional view ofthe fastener chain of FIG. 1 in anunloadedor relaxed state; and

FIG. 7 is a sectional view similar to FIG. 6 with the chain in alaterally loaded condition and showing the cooperation between thestitching threads and the slider according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention isembodied in a filamentary slide fastener indicated generally at 10 inFIG. 1 including a pair of interengagable filamentary stringers 12 and14 mounted on carrier tapes 16 and 18, respectively. The filamentarystringers l2 and 14 are each disposed along a longitudinal edge of arespective one of the carrier tapes at a woven, elongated bead 20-22formed thereon and are held securely in place by any suitable means suchas stitching threads 24 and 26, respectively, (FIG. 6).. A pull tab 28is connected to a slider, indicated generally at 30, which is disposedon tapes l6 and 18 to facilitate selective opening and closing of theslide fastener 10.

Slider 30 has a pair of parallel superposed wing members 3.2,and 34which are joined at their upper ends (as visualized in FIGS. 1 and 2) bya generally rectangular spacing member or neck 36 having its longerdimension aligned longitudinally of the carrier tapes 16 and 18. Asshown in the drawing..wing members 32 and 34 extend from neck or spacingmember 36 in cantileverfashion. Spacing member 36 has an exteriorend 38which may be formed flush with the upper edges of wings 32 and 34 and aninterior end 40 which is tapered in the plane of tapes 16 and 18 to forman apex 42. End 40 of spacing member 36 also may be tapered in a planenormal to the plane of tapes l6 and 18 to form a V-shaped edge (notshown) with the shaped edge and apex 42 joined by a smooth continuoussurface which acts to separate the interengaged stringers l2 and 14 asthe slider is moved downwardly along the fastener tapes.

Flanges 44 and 46, forming a first pair of opposing flanges, extend fromone lateral edge of each wing member 32 and 34, respectively, towardeach either; similarly, flanges 48 and 50, forming a second pair ofopposing flanges, extend from an opposite lateral edge of each wingmember 32 and 34, respectively, toward each other. Each of flanges 44,46, 48 and 50 has a longitudinal portion 52-54-56-58 (shown intransverse section in FIG. parallel to the longitudinal centerline ofthe slider 30 and an outwardly divergent portion 60-62-64-66 (shown intransverse section in FIG. 3) contiguously joined with the longitudinalportion to form an elbow 68-70-72-74 (shown in transverse section inFIG. 4). As shown in FIG. 2, each of the longitudinal and outwardlydivergent portions is substantially straight such that each of theflanges 44, 46, 48 and 50 form an obtuse angle in the plane of thecarrier tapes 16 and 18.

Angulated flanges 44, 46, 48 and 50, wing members 32 and 34, and taperedspacing member 36 cooperate to define a generally V-shaped channel forreceiving the filamentary stringers 12 and 14 of the slide fastener 10.As shown in FIG. 2, each of the flanges 44, 46, 48 and 50 is disposedsuch that the elbow member thereof is adjacent the throat of theV-shaped channel and has a chamfered inner edge 76-78-80-82 toaccommodate the configuration assumed by the fastener under a lateralload. Chamfered edges 76, 78, 80 and 82 are each in the form of a cantedplanar surface having a generally triangular periphery best seen in FIG.2. The canted planar surfaces are obliquely disposed with respect to thelongitudinal centerline of the slider 30 and to the parallel planes ofwing members 32 and 34, with the angle of the canted surfaces less thanthe angle of the divergent portions of the flanges referenced to theslider longitudinal centerline.

The planar chamfered edges 76, 78, 80 and 82 of flanges 44, 46, 48 and50, respectively specifically conform to the configuration of thesynthetic fastener chain including tapes l6 and 18, filamentarystringers l2 and 14 and stitching threads 24 and 26 especially when thechain is subjected to lateral tension as normally experienced duringclosing of the fastener. This can be appreciated from FIGS. 6 and 7. InFIG. 6, a filamentary slide fastener is shown in section with thestitching threads illustrated in an unloaded or relaxed state. While theoverall cross-sectional configuration of the stitching threads and thefilamentary stringers is generally rectangular, it can be appreciatedfrom a comparison with the diagrammatic view of FIG. 7, where thefastener is under a lateral load, that under the tension forcesexperienced in operation, the chain assumes more of an elongatedhexagonal configuration. Thus, under tension, the tapes 16 and 18 tendto be drawn away from the filamentary stringers 12 and 14 causing thestitching threads to stretch and assume an oblique profile. Under thesenormally prevalent operating conditions, the canted planar surfaces 76,78, 80

and 82 conformingly cooperate with the distorted stitching threads topromote smooth slider action and to obviate the thread wear so oftencaused by the relatively sharp-cornered flange edges heretofore used. Asa result, the present construction reduces the operational effortrequired to open and close the fastener and assures smooth slideroperation free from binding and stitching thread wear.

It is also noted the chamfered flange construction of the slideraccording to the present invention acts in a somewhat cam-like manner,especially during movement of the slider upward or in a closingdirection, for enhancing the ability of the slider to draw the separatedfastener chain halves together at the throat of the V- shaped channel.In other words, as the slider is moved upwardly, the fastener halves areforced together by the divergent portions of the slider flanges forintercoupling at the throat of the channel. The chamfered flange edgesor canted'planar surfaces 76, 78, and 82 enable the fastener chain topass through the channel without binding, as noted above, and at thesame time act on the filamentary stringers 12 and 14 in a manner topromote the desired coupling thereof. Consequently, the slider 30 of thepresent invention does not tend to distort the filamentary stringers nordoes it tend to pinch or capture individual stringer coupling elementsas was often the case in the past.

Thus, the present invention provides a slider for a filamentary fastenerhaving overall improved operational smoothness and freedom from binding,fraying and stitching thread wear. Furthermore, the slider of thisinvention conforms to the distorted configuration as sumed by fastenerchain made of synthetic materials and having modern filamentary couplingelements seron to the carrier tapes. As such, the present inventionrepresents a substantial departure from the prior art in the specificinclusion ofthe characteristics of filamentary chain both at rest andunder loading as slider design parameters.

Inasmuch as the present invention is subject to many variations, changesin details and reversal of Components, it is intended that all mattercontained in the foregoing description or shown on the accompanyingdrawing shall be interpreted as illustrative and not in a limitingsense.

What is claimed is:

1. A slider for a slide fastener having filamentary coupling elementsattached to a pair of carrier tapes by stitching threads, the slidercomprising a main body having a pair of spaced, parallel wing membersand a longitudinal center line,

a pair of flanges extending respectively from opposite lateral edges ofeach of said pair of wing members toward each other to define a channelfor slidably receiving said carrier tapes,

each of said flanges having a first portion substantially parallel tosaid center line,

each of said flanges having a second portion diverging outwardly fromsaid center line,

each of said flanges having an elbow joining said first portion and saidsecond portion, and

a single canted planar surface disposed on the inside of each of saidflanges at said elbow and extending onto both of said first and secondportions thereof, each of said canted planar surfaces forming a chamferof said elbow and defining a plane obliquely angled with respect to saidcenter line such that said canted planar surfaces permit slider tions ofsaid flanges is angled away from said center line at an angle greaterthan that made by said canted planar surface with respect to said centerline.

1. A slider for a slide fastener having filamentary coupling elementsattached to a pair of carrier tapes by stitching threads, the slidercomprising a main body having a pair of spaced, parallel wing membersand a longitudinal center line, a pair of flanges extending respectivelyfrom opposite lateral edges of each of said pair of wing members towardeach other to define a channel for slidably receiving said carriertapes, each of said flanges having a first portion substantiallyparallel to said center line, each of said flanges having a secondportion diverging outwardly from said center line, each of said flangeshaving an elbow joining said first portion and said second portion, anda single canted planar surface disposed on the inside of each of saidflanges at said elbow and extending onto both of said first and secondportions thereof, each of said canted planar surfaces forming a chamferof said elbow and defining a plane obliquely angled with respect to saidcenter line such that said canted planar surfaces permit slider movementwithout causing binding or wearing of the stitching threads.
 2. A sliderfor a slide fastener as claimed in claim 1 wherein each of saidoutwardly divergent second portions of said flanges is angled away fromsaid center line at an angle greater than that made by said cantedplanar surface with respect to said center line.